Lotus Elan and Lotus Elan Plus 2 Forums

Hi guys, first-time post, so please let me know if the answer to my question has already been done to death!

I should first tell you that I am in Australia. The S2 Elan I've just acquired has definitely lived in Oz since 1967 (and, I suspect, since 1965), and I'm trying to get it's complete history, hence this post.

My unit number scratched in the ID plate is 4193, the chassis number is, of course, 26/4193.

No engine number is recorded on this plate, but the block carries the number LP26251LBA. Looking at some posts, I seem to have too many digits, but I assure you all, that's the number.

On the LHS of the block, I've got A cast next to a clock face mark, and towards the rear I have T11. There is no L behind the RHS engine mount.

Finally (sorry!), at the rear of the head, on the "bridge" below the cam cover are some cast (not etched or stamped) details:

26E311
WM
LM8 WP

laid out exactly like that.

I'll be extremely grateful for any help that you guys can offer. It's gunna be a long resto (everything's tired and worn), but knowing the engine might be the original will be a big bonus.

Cheers,
Terry

I too have an engine number question and if I'm mistakenly hijacking someone's thread please say so politely and I'll be happy to open an separate question.

I recently purchased a Elan 26R. The car originally came with engine number #15641002. Now over the years I've learned a little about LA blocks, LB blocks etc. But until now I never gave it much thought. In the past I only worried about having enough wall thickness for the next bore job. But now I want to learn about this 8 digit number. Where do I find that number and does anyone know anymore about this engine number?

Many thanks,
Frank

26/4193 would have been equiped in 1965 with an engine SN with 4 digit I believe, so LP 26251 LBA , which is a legit elan engine number, would have been a later replacement.

Andy Graham, Lotus archivist, may be able to provide some information about your car : you should be able to contact him via the forum as LotusArchives

as for the 8 digit number on the engine of the 26R, a photo may be of help (stamping location etc), though what first comes to mind is your signature indicating 1966 26R... do you mean a GTS built from a 1966 car or chassis?

Famous Frank wrote:I too have an engine number question and if I'm mistakenly hijacking someone's thread please say so politely and I'll be happy to open an separate question.

I recently purchased a Elan 26R. The car originally came with engine number #15641002. Now over the years I've learned a little about LA blocks, LB blocks etc. But until now I never gave it much thought. In the past I only worried about having enough wall thickness for the next bore job. But now I want to learn about this 8 digit number. Where do I find that number and does anyone know anymore about this engine number?

Many thanks,
Frank

26R engines were assembled by Cosworth and BRM so I presume they used a different numbering system for them..
I know Cosworth had a type number code for their engines so the code may be 15 - engine type, 64 year 1002 engine serial number.

cheers
Rohan

Thinking about it and the low numbers of engines built for 26R's the 6410 numbers may be year and month and 02 be the engine serial number built in that month.

Maybe Cosworth can tell you more about their engine numbering system back then. Lots of other Cosworth twinks in open wheelers from the era also so maybe others know more about Cosworth engine numbers. Be interesting to see what other "original 26R" know about their engine numbers

cheers
Rohan

Terry,

Your car was invoiced by Lotus on 23rd December 1964. It was fitted with Engine No LP2625. That is in the same four number series as the surrounding cars of the era.

Frank,

Your 26R Engine No 15 64 1002 is a Cosworth number, as used on the Series 1 26Rs.

The 15 was Cosworth code for the Twincam (Mk.XV (1594 cc, wet sump, 130-140 bhp, for Lotus 26R and Lotus Cortina); 64 the year built and the next two numbers were perhaps a batch number followed by the last two numbers being the engine no itself.

Out of interest, Engine No 15 64 1006 is fitted to Tojiro Ukiya's 26-R-27 on display at the Toyota Museum in Japan in virtually original condition.

Tim

Hi everyone... do any of you have the knowledge to find out the information on this TC head?

Number on the rear is LP 741

I'd appreciate it, Paul

LP 741 does not appear to have been fitted to an Elan. Perhaps a LoCort.

It would have been in November 1963.

Tim

Hi Frank,
My 26R, S2 #40 was delivered new with a Cosworth engine which is still fitted. The car was ordered by Geoghegan & Son's and shipped to Australia for Bill Gates and Jim Bertram for use in 6 and 12 hour races. The Lotus sales record for the car has it recorded as "1600 Cosworth C13651202" with "Dry sump, steel crank and rods" also noted underneath the number.
The following is extracted from a listing of Cosworth engine types - Mk.XIII 1963 116E 1594 cc 140–150 bhp Improved Mk.XII with steel crank and rods, dry sump Formula B, Lotus 22, 23B, 23C
I understand most 26R's if fitted with Cosworth engine used the following - Mk.XV 1963 116E 1594 cc 135–145 bhp Racing Lotus TwinCam, steel crank and rods, wet sump Lotus 26R, Lotus Cortina
Regards
Vaughan

Hi,

I realize this is a fairly old thread, but there was at least one recent-ish reply, so here goes.

Does the T11 cast in the block signify anything? I’m looking at an engine that is in a Mk2 Cortina Wagon but I don’t have anything more than 1 photo and the only recognizable number is the T11. I’m trying to figure what engine this is, 105E, 109E etc and what cc it might be.


Any info much appreciated.

Ian
SoCal

The T11 refers to the casting pattern set used not to a particulalr engine type.

The bock casting number in the bottom left of the engine is your best bet for identifcation it should be something like 116E-6015 or 120E -6015 if its an early 5 bearing 1500 block as used by Lotus. If i remmeber correctly In a Mk2 cortina it may be a 681F-6015 also.

cheers
Rohan

Thanks Rohan,

I had a feeling you’d know!

Unfortunately this is the only picture I have. The seller is not exactly car literate and doesn’t understand what we would be looking for. The Cortina was bought by the current owner for the engine as a spare or replacement for the 997cc (I think) 105E in a 61 Lotus 7. I’ve bought the 7 and the engine comes with it, I’m just trying to figure out what it is. I guess once it’s here it’ll be simple enough to figure out.

Thank for the info. Any good info on tuning a 997cc 3 bearing 105E? I would like a nice free revving, lumpy, angry little donkey!

Ian

I dont think Mk2 cortinas came with 3 bearing 105E engines so most likely its a later five bearing one ? I have neverr played with the early three bearing pushrod engines but lots of work done on the 1300cc formula junior engines so data should be available.

cheers
Rohan

Hi,

You might be right! I’m having trouble nailing it down. It seems the Mk2 came with 1.2L, 1.3L and 1.5L pre-crossflow, in addition to the crossflow and V6, I’m unclear if they are 3 or 5 bearing, but I’ll quickly figure it out once it gets here.

The historic F3/FJ guys should be able help, but I also have a friend who is ex-Cosworth and has built few!

Thank you!

Ian

From the pic, and purely judging by the airbox shape, that looks like either a 1.2 or 1.3 engine. Both were fitted in Cortinas at the time. If you look at the engine number it will either start 112E or 113E which will give you the definitive answer if 1200 or 1300cc
The 1.2 and 1.3 engines though have a 3bearing crank and are not really a suitable base for tuning at all, the 3 main bearing crank setup not being up to the job and had a short main bearing life even in standard road form.
The 997cc 105E engine was never fitted in the Cortina.

A 1500cc of course has the 5bearing crank, and bored out to 1650 cc and fitted with a suitable cam makes a nice performance engine.

Alan.